PSI - Issue 78

Alessia Furiosi et al. / Procedia Structural Integrity 78 (2026) 753–760

755

Fig. 2. Geometric layout of the investigated bridge. All dimensions are in meters (Furiosi et al. 2025).

The masonry consists of soft stone (calcarenite) blocks, approximately 78 × 60 × 50 cm in size, arranged in a stretcher-bond pattern. In-situ core drilling revealed a backing layer made of masonry stone covering the arch barrels, with a backfill made of loose coarse material above. Due to the absence of detailed data on the spandrel wall thickness, its height variation, and the resulting backfill profile, the spandrel walls were assumed to be tapered, with thickness varying from 1.5 m at the base to 1.0 m at the top (Torre, 2003). In Fig. 2 the fundamental geometric parameters of the studied bridge are summarized. 3. Substructural numerical model generation A DEM-based numerical approach is employed in this work to simulate the structural behavior of a masonry arch bridge. DEM is particularly suited for analyzing masonry structures, as it accurately captures the discrete nature of the material by representing it as an assembly of rigid or deformable blocks, allowing for block separation, large relative displacements, rotations, and automatic detection of joined and non-joined contacts. Originally developed by Cundall and Hart (1992), the method has been extensively validated for both static and dynamic analyses of masonry structures, highlighting the influence of modeling assumptions on simulation accuracy (Sarhosis et al. 2020, Saygılı and Lemos 2021). The three-dimensional numerical model representative of critical areas of the existing masonry arch bridge was developed by using the commercial software 3DEC (version 9.2.23) (Itasca Consulting Group Inc. 2024).

Fig. 3. Details of the modeled portion of the masonry arch bridge: front view.